Non-transecting anastomotic augmented uretroplasty with dorsal onlay buccal graft for the treatment of bulbous urethral strictures: Results and complications

doi:10.21203/rs.3.rs-4960446/v1

Introduction : Urethroplasty is the gold standard for the management of urethral strictures. For obliterative bulbar strictures longer than 2 cm, excision primary anastomosis (EPA) cannot be optimally performed, and staged urethroplasty is recommended. To minimize multiple interventions, Augmented Anastomotic Urethroplasty (AAU) was developed. Incorporating the vessel-sparing approach without the transection of the spongiosum would improve the results of urethroplasty and limit complications. Our study aimed to assess the outcomes of non-transecting Anastomotic Augmented Urethroplasty with a buccal graft (ntAAU).

Method : From 2019 to 2023, 42 patients underwent ntAAU. Anatomical success was defined as the ability to pass a cystoscope (16,5 Fr) and functional success was determined by a maximum urinary flow rate (Qmax) greater than 15 ml/s. Clinical outcomes were evaluated using patient reported outcome concerning urinary function (USP dysuria, VPPS, six items LUTS, questions 7, 9, 10 from USS-PROM) and erectile function (IIEF-5, EHS).

Results : Anatomical success rate was 90.5% and functional success was 83.3% with a median (IQR) follow-up of 18 (12.5–28.5) months. The complication (urinary infection, suprapubic catheter obliteration, abscess, bleeding) rate was 14.2%. Questionnaires were avaiblable for 31 patients. Median (IQR) USP dysuria score was 0 (0–1), VPPS score was 7 (3–12), and six-item LUTS score was 4 (2–9). The median (IQR) IIEF-5 score was 22 (15.5–25) and EHS score was 3.5 (2–4). Patients with treatment failure were managed with redo-urethroplasties.

Conclusion : This technique shows good outcomes and appears to be a valuable option for managing long strictures with an obliterative part.

Urethral Stricture

Urologic Surgical Procedures

Erectile dysfunction

Patient Reported Outcome Measures

Bulbar stricture is the most common location for urethral strictures in men(1).

The length and severity of the stricture are critical factors in determining the appropriate treatment. Severe strictures, known as nearly obliterative (1–3 Fr) or obliterative (no urethral lumen − 0 Fr) (2), are poorly managed with endoscopic treatments such as dilation or urethrotomy. Urethroplasty is the gold standard for these cases, with a long-term success rate of up to 80% for primary repairs (2). There are two basic principles of surgical urethroplasty : anastomotic urethroplasty and urethroplasty using buccal grafts, in augmented (one-stage) or substitution (two-stage) fashion.

Short obliterative or nearly obliterative bulbar strictures (≤ 2 cm) usually undergo excision primary anastomosis (EPA) (3).

Non-transecting EPA (ntEPA) techniques, based on the principle of vascular preservation of antegrade and retrograde arterial blood supply, has been developed to reduce ischemia of the urethroplasty and sexual morbidity. (4).

For obliterative bulbar strictures longer than 2 cm, EPA results in anastomosis with tension, ventral curvature of the penis, and high failure rate (3). In this case, the traditional method was two-stage urethroplasty with buccal graft (3). To minimize multiple interventions, the concept of Augmented Anastomotic Urethroplasty (AAU) was developped (4). AAU involves excising and anastomosing the narrowest part of the stricture and augmenting it with a graft on the opposite side. This technique yiels good outcomes for strictures longer than 2 cm with a shorter obliterative segment (5). The principle of vascular preservation can be applied to AAU and is called Non-Transecting Augmented Anastomotic Urethroplasty (ntAAU)(4).

Our study aimed to assess the outcomes of ntAAU in terms of urethral patency and morbidity in a patient cohort.

From April 2019 to November 2023, 224 urethroplasties were performed in a tertiary academic center for urethral reconstruction. We identified 42 patients who underwent ntAAU with BMG by a single surgeon.

Demographic data were collected (age, BMI, ASA score, smoking status, diabetes, history of hypertension, and radiotherapy), stenosis characteristics including etiology, retrograde uretrography (RUG), voiding cystourethrography (VCUG) and fibroscopic characteristics). Previous treatment modalities, current bladder emptying modalities, operative details, and postoperative follow-up were collected using the patient’s medical field.

Preoperatively, all patients underwent a complete workup including flowmetry, RUG and VCUG. NtAAU was performed in cases of bulbar stricture > 1 cm with a nearly obliterative or obliterative segment.

Surgery was performed with the patient in the lithotomy position, involving a vertical incision over the median raphe. The urethra was mobilized (6) by dissecting the bulbocavernosus muscles while preserving the lateral structures. The stricture was identified using a 20 Fr catheter, followed by a dorsal urethrotomy (Fig. 1). The stenotic area (mucosa and spongiofibrosis) was superficially excised, sparing the spongiosa. The healthy mucosa was then anastomosed in an inlay fashion using a 6.0 polydioxanone suture.

The harvest of cheek buccal mucosa graft was done according to the standard technique.

The graft was secured to the urethroplasty site on the corpora cavernosa with 3/0 sutures. The urethral margins were anastomosed to the buccal mucosa graft with a running 5/0 polydioxanone suture, and additional separate sutures were placed at the ends.

The procedure concluded with the insertion of a suprapubic catheter. One week postoperatively, the urethral catheter was removed and a voiding cystourethrography (VCUG) was performed through the suprapubic catheter at 3 weeks (Fig. 2). The catheter was removed if no extravasation was observed. To enhance graft uptake, postoperative treatment with PDE5 inhibitors (tadalafil 5 mg daily) was prescribed after catheter removal for 6 months to 1 year, regardless of immediate postoperative sexual function.

Post-operatively, the success of urethroplasty is evaluated using both anatomical and functional criteria. Anatomical success is defined as the ability to pass a cystoscope (OLYMPUS CYF-VH 16.5 Fr.) through the urethroplasty site. Functional success is determined by a maximum urinary flow rate (Qmax) greater than 15 ml/s.

Post operatively, patients were asked to fill specific questionnaires to evaluate lower urinary tract symptoms and erectile function. The VPSS ranges from 0 to 24 points, with scores of 0 to 7 considered mild. The Visual Prostate Symptom Score (VPSS) has shown a good correlation with both Qmax and urethral diameter (7).

The Urinary Symptom Profile (USP) - dysuria part - ranges from 0 to 9 points. The six-item LUTS score also ranges from 0 to 24 points. Additionally, questions 7, 9 and 10 derived from the Urethral Stricture Surgery Patient-Reported Outcome Measures (USS-PROM), validated for post-urethroplasty symptoms, were used.

Erectile function was assessed using the Erectile Hardness Score (EHS), which ranges from 1 to 4 points and applies to all patients, and the IIEF-5, which ranges from 1 to 25 points and applies only to sexually active patients.

Complications were classified as minor or major according to the Clavien-Dindo classification and as early (< 30 days) or late (> 30 days).

Descriptive analyses were conducted for baseline, stricture, and surgical characteristics. Data were expressed as mean ±SD, median (IQR) and number with percentage as appropriate. Wilcoxon matched-pairs signed-rank test was used to compare the distribution of baseline and postoperative uroflowmetry parameters. P-values were two-sided, and statistical significance was set at P < 0.05.

Our institutional ethics review board approved this study (CNIL 2231047).

ntAAU with BMG was performed in 42 patients. Population characteristics are presented in Table 1. Age at surgery was 47 (30–64) years. Mean (SD) body mass index was 24.1 (3,7) kg/m². The etiology was iatrogenic in 38% of cases, with endoscopic maneuvers, radiation-induced therapy, catheter-induced injury and hypospadias accounting for 21.4%, 2.3%, 9.5% and4.7% of cases, respectively.

Regarding previous stricture treatments, 35 patients (83.3%) had undergone multiple (>2) dilatations and/or urethrotomies, while 6 patients (14.2%) had a history of prior urethroplasty, including Augmented Urethroplasty (AU) with BMG, EPA, or unknown type respectively in 7.1%, 2.3%, and 4.8% of cases. All stricture location were bulbar. The mean (SD) stricture was 19.8 mm (11.1). All patients complain of obstructive symptoms of the lower urinary tract. Qmax was 4,3 (3,2-5,6) ml/s and 11 of them (26.2%) had preoperative suprapubic catheter.

Anatomical and functional outcomes

The anatomical success rate was 90.5%, with a median (IQR) follow-up of 18 (12.5-28.5) months. Functional success was 83.3%, with 8 patients having a Qmax < 15 ml/s. Among these, 4 patients also failed the anatomical criterion while the other 4 patients did not report LUTS symptoms (mean LUST score of 7,25) or dysuria (mean USP dysuria score of 0,5)

The median (IQR) post operative Qmax was 20 (15,6-28,8) ml/s (p= 0.0007). The median (IQR) duration of hospitalization was 2 (1-2) days.

Six (14.2%) patients experienced an early complication (urinary infection, suprapubic catheter obliteration, abscess, bleeding) including 2 major Clavien-Dindo III complications (hematuria and abscess necessitating reoperation).

The 4 patients (9.5%) with anatomical faillure were treated with redo-uretroplasties (3).

Patient-Reported Outcome (Table 3)

The scores and detailed responses to every question are provided in Table 2. Of the 42 patients, 31 (73,8%), including 3 of the 4 patients with anatomical failure, responded to the questionnaire. The median (IQR) VPSS score was 7 (3-12), and median (IQR) USP dysuria was 0 (0-1). The median (IQR) six-item LUTS score was 4 (2-9). 87% patients were satisfied or very satisfied with the outcome their surgery.

The median (IQR) EHS score was 3,5 (2-4) and the median (IQR) IIEF-5 score was 22 (15,5-25). 6 patients with a follow-up of less than 1 year are still under PDE5 inhibitor treatment. No patients reported ventral curvature.

The anatomical success rate of our cohort is 90.5%, and the functional success rate is 83.3%, with a median follow-up of 18 (12.5–28.5) months. With 42 patients, this is the third-largest of five series on ntAAU(8–12).

Similar success rates, ranging from 82.4–100%, have been observed with median follow-up of 11.5 to 58 months (Table 3). However, the need for retreatment was frequently used as a criterion (8, 10–12), but this is subject to numerous biases. As recommended, we used a composite criterion incorporating both anatomical and functional measures to define "success" after urethral surgery (13).

The length of treated strictures varies widely, with median ranging from 1 cm (11) to over 4 cm (8). In our study, the median stricture length was 19.8 mm, which is within the range described for this technique.

The dorsal onlay technique is the preferred method in our study, as also used by Bogdanov, Joshi and Welk (9, 10, 12). Graft positioning (dorsal vs ventral) remains a subject of debate, but it does not appear to impact the final outcome (8, 14, 15).

During the study inclusion period, Joshi et al. (12) advanced the ntAAU concept by introducing a technique that avoids mucosal resection, called Mucosal-sparing augmented non-transected anastomotic (MsANTA) with similar outcomes. They argue that while the arterioles in the corpus spongiosum remain intact, the connections between the corpus spongiosum and the urethral mucosa are disrupted during resection. However these results require further investigation.

Furthermore, these ntAAU results are similar to transecting AAU (Table 3). Granieri et al. (16), found a patency rate of 92.9% with a median follow-up of 12.1 months. Kahokehr et al. (17) observed a patency rate of 91.1% with a median follow-up of 28 months. However both studies used the absence of reintervention as the criterion for success which may have overestimated their results. No studies have directly compared the outcomes of AAU and ntAAU techniques. However, the success rates appear to be similar.

Vascular preservation is important for maintaining the vascularization of the urethroplasty and would contribute to increasing the success of the procedure. Unlike ntEPA alone, ntAAU has the added advantage of using a graft to widen and treat a longer segment of the urethra. By combining the benefits of previous methods, ntAAU addresses the most stenotic area, which are key sources of recurrence, while also allowing for the augmentation of the less obstructive residual stricture.

Additionally, emerging evidence indicates that untreated upstream metaplasia can lead to recurrence, a challenge addressed by the ntAAU technique, unlike ntEPA. Resection should be carried out until healthy urothelium is achieved.(18). As metaplasia increases the length of the urethra requiering treatment, more cases arise where strictures exceed 2 cm, making EPA insufficient and necessitating the use of AAU techniques.

Given the comparable recurrence rates among different techniques, the focus has shifted to erectile function. Many studies show no significant difference between transecting and non-transecting techniques, though there is a trend favoring non-transecting (1, 19–23) .

In the AAU cohorts, erectile dysfunction (ED) was either not standardized (16) or not described (17). In the Granieri cohort (16), the rate of sexual dysfunction was reported to be 10% (Table 3). Our cohort had an IIEF-5 score of 22 (15.5–25). Marks (8) reported median (IQR) IIEF-EF scores of 24 [14–30]. Welk et al. (10) found 27% of participants experienced erectile discomfort, but no cases of erectile dysfunction, similar to the findings of Palminteri (11), although the criteria used were not specified. This variability in evaluation criteria and lack of standardized data collection make it difficult to draw definitive conclusions. However, the data cmcmon erectile dysfunction and sexual disorders are inconsistent and poorly documented (Table 3), preventing generalization.

The main limitations of our study are its retrospective nature and the absence of a comparative analysis. A study involving multiple practitioners and longer follow-up seems necessary to draw reproductibility and long term effectiveness on this technique.

Our ntAAU cohort shows good outcomes in term of uretral patency and erectile function.

It appears to be a valuable option to consider for long strictures with a obliterative part. Mastery of this technique is valuable when NtEPA and AU are not optimally feasible, as it preserves the benefits of non-transection and augmentation.

Author Contribution

A.B. wrote the main manuscript text.A.B., A.S., F.M., and C.G. collected the data and developed the methodology.T.L., P.N., and B.B. reviewed and provided critical revisions to the manuscript.

Data Availability

Data tables and statistical analysis will be made available in supplementary information files following publication

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Table 1 : Baseline characteristics

Characteristics	Values
*Preoperative*
Age, years, median (IQR)	47 (30-64)
Body mass index, kg/m2, mean (SD)	24.1 (3.7)
*Stricture etiology*
Idiopathic Trauma Iatrogenic Lichen sclerosus Infectious	18 (42.9%) 6 (14.2%) 16 (37.9%) 1 (2.4%) 1 (2.4%)
*Stricture characteristics, n (%)*
History of uretrotomy or dilatation History of urethroplasty Stricture length, cm (sd)	35 (83.3%) 6 (14.2%) 19.8 (11.1%)

*Preoperative uroflowmetry status, n (%)* Adequate uroflowmetry, ml/s Suprapubic catheter	3.6 (3-7) 11 (26.2%)

Table 2 : Post operative patient reported outcome about urinary and erectile satisfaction

Questionnaire	Values	Min-max
*Total VPSS-score ; median (IQR)*	7 (3-12)	0-24
*USP-Dysuria ; median (IQR)*	0 (0-1)	0-9
Six-item LUTS score ; *median* (IQR)	4 (2-9)	0-24
*n° 7 Overall, how much do your urinary symptoms interfere with your life ? /5*	1 (0-1)	0-3
*n°9 Do you feel anxious because of your urinary problems ? n (%)* Not at all A little Moderately, Significantly, Extremely	13/31 (43%) 8/31 (27%) 6/31 (20%) 3/31 (10%)
*n° 10 Are you satisfied with the outcome of your operation ? n (%)* Satisfied or very satisfied Unsatisfied or very unsatisfied	27/31 (87%) 4/31 (13%)
*EHS score ; median (IQR)*	3,5 (2-4) *	1-4
*IIEF-5 score ; median (IQR)*	22 (15,5-25)	1-25
* on a population of 30, after exclusion of one patient presenting with manifest erectile dysfunction preoperatively

Table 3 is available in the Supplementary Files section.

No competing interests reported.

Table3.docx

Non-transecting anastomotic augmented uretroplasty with dorsal onlay buccal graft for the treatment of bulbous urethral strictures: Results and complications

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Abstract

Figures

Introduction

Patients and method

Results

Discussion

Conclusion

Declarations

Author Contribution

Data Availability

References

Tables

Additional Declarations

Supplementary Files

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